p {
    margin: 0;
}

.myClass {
    /*居中*/
    display: flex;
    justify-content: center; /*垂直居中*/
    align-items: center; /*水平居中*/
    margin-bottom: 20px;
}

#myCheckBox {
    text-align: center;
    font-size: 20px;
    color: #477998;
}

body {
    background-color: #f9f2e7;
}

/* 标题 */
h1 {
    text-align: center;
    font-size: 60px;
    color: #477998;
}

/* 游戏内容容器 */
.container {
    position: relative;
    width: 471px;
    height: 471px;
    margin: 0 auto;
}

/* 游戏获胜信息面板 */
.game-message {
    display: none;
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: rgba(69, 133, 136, 0.4);
    text-align: center;
}

/* winner 获胜者 */
.game-message p {
    margin: 180px 0 40px 0;
    color: #fff;
    font-size: 50px;
}

/* 重新开始游戏按钮 */
.game-message button {
    color: #517304;
    border-color: #517304;
    width: 110px;
    height: 40px;
    font-size: 20px;
    cursor: pointer;
}

/* 游戏面板棋盘 */
.game-board {
    width: 471px;
    height: 471px;
}

.game-board.x .cell:not(.x):not(.o):hover::before {

    content: 'X';
    color: lightgray;
}

.game-board.o .cell:not(.x):not(.o):hover::before {
    content: 'O';
    color: lightgray;
}

/* 棋盘 - 行 */
.row {
    display: flex;
}

.row:last-child .cell {
    border-bottom: 0;
}

/* 棋盘 - 单元格 */
.cell {
    flex: 1;
    box-sizing: border-box;
    width: 157px;
    height: 157px;
    line-height: 157px;
    border-right: 6px solid #546363;
    border-bottom: 6px solid #546363;
    text-align: center;
    cursor: pointer;
    /*font-size: 88px;*/
    font-family: 'Gill Sans', 'Gill Sans MT', Calibri, sans-serif;
}

.cell:last-child {
    border-right: 0;
}

/* x 玩家 */
.cell.x::before {
    content: 'X';
    color: #01a8c6;
}

/* o 玩家 */
.cell.o::before {
    content: 'O';
    color: #8fbe01;
}
